It was envisaged through the London Government Act 1963 that Lewisham as a London local authority would share power with the Greater London Council. The split of powers and functions meant that the Greater London Council was responsible for "wide area" services such as fire, ambulance, flood prevention, and refuse disposal; with the local authorities responsible for "personal" services such as social care, libraries, cemeteries and refuse collection. This arrangement lasted until 1986 when Lewisham London Borough Council gained responsibility for some services that had been provided by the Greater London Council, such as waste disposal. Lewisham became an education authority in 1990. Since 2000 the Greater London Authority has taken some responsibility for highways and planning control from the council, but within the English local government system the council remains a "most purpose" authority in terms of the available range of powers and functions.

In 2012 the Council was fined £70,000 by the Information Commissioner's Office (ICO) after a social worker "left files containing GP and police reports and allegations of sexual abuse and neglect in a shopping bag on a train".[1] Commenting on Lewisham and other authorities who had made similar data protection breaches, the ICO said "It would be far too easy to consider these breaches as simple human error. The reality is that they are caused by councils treating sensitive personal data in the same routine way they would deal with more general correspondence. Far too often in these cases, the councils do not appear to have acknowledged that the data they are handling is about real people, and often the more vulnerable members of society."[1] In August 2015, it was reported by the News Shopper that between April 2011 and April 2014, Lewisham Council had disclosed the public's sensitive data sixty-four times.[2] However, the neighboring councils Bromley, Bexley and Greenwich did not commit any data breaches.[2]

In December 2015 it was reported by The Guardian that the Mayor of Lewisham predicted that casualties of the next round of cuts would include youth work, libraries, parks, crime reduction, social care and street cleaning.[3] In February 2016, Lewisham Council announced that it would be raising Council Tax by 3.99 percent in order to help meet the 15 million pounds of savings that is required each year.[4]